A conventional inkjet recording apparatus having an ink circulation type of an inkjet head capable of preventing deterioration of ink and settling of color material and capable of improving discharge stability of the ink as a liquid discharge apparatus is known. The inkjet recording apparatus includes an ink supply circulation module which supplies ink in an ink tank to the inkjet head and returns the ink supplied to the inkjet head to the ink tank without making the ink stay in the vicinity of a nozzle to circulate the ink in a circulation circuit.
The ink supply circulation module is a diaphragm pump for conveying fluid by combining a reciprocating motion of a diaphragm made of a piezoelectric member, a rubber, a thermoplastic resin or Teflon (registered trademark) and an operation of a check valve made of resin to supply the ink in the ink tank to the inkjet head.
In the diaphragm pump which conveys the liquid through the reciprocating motion of the diaphragm, suction and discharge of the liquid are alternately performed, and the liquid flows intermittently, and thus, pulsation is generated. There is a possibility that the pulsation disturbs a negative pressure for forming a meniscus in the nozzle of the inkjet head, resulting in disorder of ink droplets discharged from the nozzle.